1. Technical Field
N/A
2. Description of Related Art
The present invention relates to a buckle allowing easy length adjustment of a head strap. The buckle primarily comprises a base, a pressing board that is engaged with the base and has a swingable rear end, and an operating member engaged with the base, such that the operating member is aligned with the back of the pressing board and two buttons of the operating member are jutting out of the base, while an arcuate bar linking the two buttons presses against the back of the pressing board. Thus, a user can use his/her two fingers' opposite, inward, small movements, which press the two buttons inward the base, to make the arcuate bar push the rear end of the pressing board outward, in turn easily causing a clutch portion at the rear end of the pressing board to depart from a tooth formed on the head strap which it originally clutches.